<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>01_BOM操作</title>
</head>
<body>
  <button onclick="alert('请先登录')">弹出警告框</button>
  <button onclick="confirm('是否确定删除')">弹出确认框</button>
  <script>
    console.log(parseInt(6.6));
    console.log(parseInt(6.1));
    console.log(parseInt(6));
    console.log(parseInt('6.99'));
    console.log(parseInt('hhh'));

    console.log(parseFloat(6.6));
    console.log(parseFloat(6.1));
    console.log(parseFloat(6));
    console.log(parseFloat('6.99'));
    console.log(parseFloat('hhh'));

    console.log(isNaN(6.6));
    console.log(isNaN(6));
    console.log(isNaN('6'));
    console.log(isNaN('hhh'));1
  </script>
</body>
</html>